Rainfall

Cyclonic Rainfall Cyclone is the specific air formation when the pressure at an area is less than the surrounding regions.  It is formed when two masses of air of different temperature , humidity , and density meet. Warm air and cool air do not mix as they have different densities. The warm air rises over the heavier cool air.  Warm air from the surrounding regions comes to the centre of the cyclone and starts moving upward.  As it rises, the temperature of the air reduces.  Then condensation occurs resulting in cyclonic rainfall.  They are cyclonic and stormy in nature .

Orographic Rainfall Winds coming from lakes or seas are moisture laden.  They are obstructed by high mountain ranges. They start going upward along the slope of the mountain.  The temperature of these winds drops as they go higher causing condensation, resulting in the formation of Orographic clouds . The rain pouring from these clouds is called Orographic rainfall. Windward side of mountain receives more rain, leeward receives less. The leeward side is also called the rainshadow region. Watch the process of Orographic rainfall in the video above.

Convectional rainfall In equatorial regions, the surface gets heated and the air near it also heats.  It then spreads and becomes lighter moving upward.  The air cools down, when it goes upward.  The moisture holding capacity of cold air is less.  When the condensation point is reached large cumulonimbus clouds are formed. Consequently, condensation of water vapor occurs and convectional rainfall occurs.  Convectional rains are accompanied with lightening and thunder.  Watch the process of convectional rainfall in the video above.

What is rainfall? The temperature of the water vapor  reduces when it goes higher. Condensation of the vapor  occurs.   The water vapor gets condensed to form water droplets. Clouds form when the condensed water droplets and the dust particles accumulate.  The water droplets increase in size. When they cannot float in the air anymore because of their weight, they come down.  Water droplets falling  from the clouds is called precipitation.   Precipitation  can happen in any form. The different forms of precipitation are  rain , snow, hail and sleet. Rain is the major component of  the water cycle and is responsible for depositing most of the fresh water on the Earth.